Serbian police officers of the Special Anti-Terrorist Unit pose for a picture in their base outside Belgrade October 8, 2014. When the killing of an unarmed black teenager by a white policeman in Ferguson, Missouri, in August sparked sometimes violent protests, the response of police in camouflage gear and armoured vehicles wielding stun grenades and assault rifles seemed more like a combat operation than a public order measure. Some U.S. police departments have recently acquired U.S. military-surplus hardware from wars abroad, but there are many law enforcers around the world whose rules of engagement also allow the use of lethal force with relatively few restrictions. But for every regulation that gives police wide scope to use firearms, there is another code that sharply limits their use. In Serbia, police may use measures ranging from batons to special vehicles, water cannon and tear gas on groups of people who have gathered illegally and are behaving in a way that is violent or could cause violence, but they may use firearms only when life is endangered. (Photo by Marko Djurica/Reuters)

Londoners enjoy a “Silent Night” as Big Ben falls silent, London, UK on August 21, 2017. ose Allerston from Clapham, London said “After a stressful day in the office, I couldn't think of anything better than going home and climbing into bed – but when I saw this bed opposite Big Ben I just couldn't resist getting in for a snuggle”. (Photo by Imagewise Ltd/Rex Features/Shutterstock)

A French riot police officer is surrounded by flames, during a demonstration against the controversial labour reforms of the French government in Paris on September 15, 2016. Opponents of France's controversial labour reforms took to the streets on September 15, 2016 for the 14th time in six months in a last-ditch bid to quash the measures that lost the Socialist government crucial support on the left. Scores of flights in and out of France were cancelled as air traffic controllers went on strike to try to force the government to repeal the changes that became law in July. (Photo by Thomas Samson/AFP Photo)

A police officer detains a person during protest by supporters of Pakistan's former Prime Minister Imran Khan against his arrest, in Karachi, Pakistan, 09 May 2023. Khan, the chairman of Pakistan Tehreek-e-Insaf, was taken into custody by the National Accountability Bureau (NAB) on 09 May outside the Islamabad High Court, where he had arrived to appeal for bail in multiple cases filed against him. The arrest came after Khan's ouster from power in April 2020 following a failed vote of confidence in parliament. (Photo by Rehan Khan/EPA)

Pregnant Tibetan antelopes move across the Qinghai-Tibet highway in Hoh Xil, northwest China's Qinghai Province, May 29, 2023. A growing number of pregnant Tibetan antelopes are migrating to the heart of northwest China's Hoh Xil National Nature Reserve to give birth, according to the reserve's management office. Every year, tens of thousands of pregnant Tibetan antelopes start their migration to Hoh Xil in around May to give birth and leave with their offspring in late July. (Photo by Xinhua News Agency/Rex Features/Shutterstock)

Shi'ite fighters launch a rocket during clashes with Islamic State militants on the outskirts of al-Alam March 8, 2015. Thaier Al-Sudani: “It was me and a few other Iraqi journalists working for local outlets. We went to the frontlines in coordination with the Iraqi government forces and supporting militias. The press officer would come in the morning and take us to the frontline in a convoy. Whenever an area was won from Islamic State, the fighters would chant and pray and show victory signs. Most of the areas we were in didn't have residents, so after the battle they would resemble ghost towns; nothing but burnt cars and charred bodies of Islamic State fighters. Al-Alam was an exception as it had some residents who chanted for the government forces after their victory”. (Photo by Thaier Al-Sudani/Reuters)

This handout picture released by the Icelandic Coast Guard on May 29, 2024 shows billowing smoke and flowing lava pouring out of a new fissure, during a surveilance flight above a new volcanic eruption on the outskirts of the evacuated town of Grindavik, western Iceland. (Photo by Icelandic Coast Guard/Handout via AFP Photo)

A motorcycle modified to run on rails is seen inside a tunnel connected to the Altiplano Federal Penitentiary and used by drug lord Joaquin “El Chapo” Guzman to escape, in Almoloya de Juarez, on the outskirts of Mexico City, July 15, 2015. U.S. law enforcement officials met with agents of the Mexican attorney general's office this week to share information related to the escape from prison of Guzman and coordinate efforts to apprehend him, a Mexican government official said on Wednesday. (Photo by Edgard Garrido/Reuters)